Motion-picture reel end indicator



Jan. 6, 1953 c.- w. HATKE PICTURE REEL END INDICATOR MOTION- 2SHEETS-SHEET 1 Filed Aug. 11, 1950 INVENTOR. CHARLIE? h. H 7705 ATTORNEYJan. 6, 1953 c. w. HATKE 2,624,306

MOTION-PICTURE REEL END INDICATOR Filed Aug. 11, 1950 2 SHEETS-SHEET 2IN V EN TOR. 6mm 5 MAW/(E ,rroe/ver Patented Jan. 6, 1953 UNITED STATESPATENT OFFICE-,9

MOTION-PICTURE REEL END INDICATOR Charles W. Hatke, .Denver,:Cl0.Application August 11, 1950,.SerialTNo. 178,847

7Claims.

1 This invention relates to a device for giving an audible signal as theend of a reel of motion picture film is approached in a projector. Theprincipal object of the invention is to provide a simple and highlyefficient device which can be attached to any of the conventional filmmagazines, and which will give a series of audible signals asthe end ofthe reel is approaching, to amply warn the operator when the reel willbe completed.

Another object of the invention isto provide a mechanism of thischaracter which will operate from freely rolling balls under theinfluence of gravity, so that the uncertainties of springs and othermechanical elements will be avoided.

A further object is to so construct the device that the operator cannote at any time how much time remains on the running reel, and toprovide means for automatically removing the signal device from the reelwhen the door of the film magazine is opened so that it willnotinterfere with .the'removal and replacement of the reels.

Other objects and advantages reside in the detail construction of theinvention, which is designed for simplicity, economy, and efficiency.These will become more apparent from thefollowingflescription.

In. the following detailed description of the invention, reference ishad to the accompanying drawing which forms a part hereof Lik numeralsreferto like parts in all views ofthe drawing. and throughout thedescription.

In the drawings:

Fig. 1 is a side View of afilm magazine of a conventional motion pictureprojector, with its door. partially opened, illustrating the inventionin place'thereon Fig/2' is an enlarged front view of theimproved reel.end'indicator;

'Fig. 3 is a side view of the indicator;

' Fig. '4 is a rear view thereof;

' Figs.'5, 6, '7, and 8 are vertical sections, taken'on"th'e'-line-8--8, Fig; 3, indicatingvarious successive positions ofthe signaling'mech'anism;

"Fig.9 is 'a similar section,taken"on the'line '9-9, Fig. 3 and Fig; -10is a'vertical cross-sectiontaken entire line IO-10, Fig. 2.

in Fig. 1 the film magazine" of a conventional motion picture projectoris indicated at H), with a film reelat ll and the roll of'film' thereon"at "t2. Such magazinesare providedwith circular hinged doors I 3 "forcompletelyopening and closing the magazines. In Fig. *1 the doorl3-isillustrated in the partially opened position.

The improved signaling device employs .a sector-shaped dial plate l4provided with a peripheral time scale 43. The dial plate Hi terminatesat'its bottom in a circular spacing boss l5. A'hollow'threaded studliiis mounted in the boss I5 and projects forwardly therefrom through asuitable "receiving opening which is drilled or otherwise'formed in-theback of themagazine it. The-hollow threaded stud I5 is provided with aclampnut H by'means of'whichztheboss i5 is clamped to'the back of themagazine It.

. An operating shaft [8 extends throughout the length of the hollow studl6 and projects from both extremities of the latter. The rear extremityof the operating shaft is turnedupwardlyto form a lever arm l9, thenceupwardly over the front face of the:plate M to form a pointer 2| toindicate positions on the time scale 43. The forward extremity of theshaft It carries a film follower arm 22 which is secured to the formerat any desired radial position by means of .set screws The freeextremity of the follower arm enters between the sides of the reel I!and terminates in a freely rotatable rubber roller 24 which bearsagainst theroll of film l2 so as to swing toward the'axis of the reel lI as the film unreels and the roll o'f'film decreases in size.

A segment gear plate 25 is .rotatably mounted on'the rearward portionofthe operating shaft iii and extends upwardly therefrom into meshwith-a toothed pinion 26.

Two lugs 44 are formed on the'segmentgear, there being one lugpositioned on each side of the lever arm 19. The lugs are provided withtwo oppositely facing set screws 21 which can be brought into contactwith opposite sides of the lever arm 19 so as to adjust the relativepositions of the segment gear and v:the lever arm and to cause thesegment gear to move in unisonwith the lever arm. The segment .gear25 isslotted, as indicated at 28, for the pasbell 13l' is fixedly secured onthe rear extremity of the shaft screw 30. The screw 38 also supports aball guide plate 33 having a projecting hub '32. The bell 3i and the hub32 are fixedly secured together on the screw tflby means of a clamp nut34. The ball guide plate 33 is positioned-completely :within theconfines of the bell 3|. The backing plate 29 is also provided with aprojecting hub 35 which rotates on the screw 30 and which is heldseparated from the ball guide plate 33 by means of a separating spring35.

Thus, it can be seen that the ball guide plate 33 and the bell 3i remainstationary While the backing plate 29 rotates under the influence of thesegment gear 2?; and pinion 26.

The forward face of the ball guide plate facing the backing plate isprovided with a concentric, semi-circular guide flange ill whichterminates at its upper extremity above the shaft screw in an inclinedball chute 38 which extends across the shaft screw 3&3 to the oppositeside of the ball guide plate 33, where it terminates above the upperextremity of an inclined platform flange 39. The platform flange 39terminates below the shaft screw 36 above the lower rim of the bell. Aball stop member 45 extends downward from the lower extremity of theflange 39 toward the lower rim of a bell 3!. The backing plate 29 isprovided with a rearwardiy projecting boss ll! and a peripheral ballpocket ii. Two freely rolling steel balls 42 are positioned between thebacking plate 29 and the ball plate 33.

It can be seen that as the film reel I? decreases in diameter, the arm22 will swing under the influence of gravity toward the axis of the reelII, and the pointer 2! will move to the left in Fig. 1, indicating onthe scale t3 the minutes remaining on the reel E2. The backing platewill also be rotated in a clockwise direction in Figs. 6 to 8,inclusive. The rotation of the backing plate 29 causes the two steelballs 52 to be carried upwardly in the pocket ii along the guide flange37, as shown in Figs. 5 and 5. The balls continue to move upwardly overthe guide flange til as the film uni-eels until the foremost ball passesover the top of the flange 3? onto the chute 33.

from the extremity of the latter to again strike the rim of the bell illto produce a second single bell tone, as shown in Fig. 8. As the filmcontinues to unreel, the ball guide plate will carry the second ball 42to the top of the inclined chute 38, from whence it will rol" to strikethe bell 1 once at the extremity of the chute 33, as indicated at A,Fig. 8. It will then fall to the inclined platform 39 and roll down thelatter and fall from the extremity of the platform to strike the bell asecond time, as indicated at B, Fig. 8. The two balls it rest againstthe ball stop 45 until the device is re-set to bring the ball pocket 41back beneath the balls to the starting position of Fig. 6.

Thus, it can be seen that three separate audible signals areproduced-two single bell strokes followed by a double bell stroke. Thesecan be arranged for any desired intervals, such as one stroke indicatingtwo minutes remaining; a second single stroke indicating one minuteremaining; and a final double stroke indicating fifteen secondsremaining. The time settings can be adjusted by varying the position ofthe arm 22 on the shaft 58 by means of the set screws 22-3 and byvarying the relative positions of the lever 4 arm I9 and the segmentgear plate by means of the set screws 21.

It will be noted that it is impossible to remove the reel 1 I while thefollower arm 22 is positioned between the sides of the reel, as shown inFig. 1, without damage to either the arm or the reel or both. In orderto prevent this, a flexible member, such as a chain as, is secured atits one extremity to the pointer 25 and at its other extremity to a postAll mounted on the magazine lid l3. The length of the chain is such thatwhen the lid is opened sufficiently to permit removal of the reel H, thepointer 2! will be pulled to the right in Fig. 1 sufilciently to liftthe follower arm 22 completely from the confines of the reel l I. Whenthe lid is closed, the follower arm will be lowered until its roller 24rests on the roll of film.

While a specific form of the improvement has been described andillustrated herein, it is to be understood that the same may be varied,within the scope of the appended claims, without departing from thespirit of the invention.

Having thus described the invention, what is claimed and desired securedby Letters Patent is:

1. A film reel alarm and indicator for attachment to the film rollmagazine of a motion picture projector, comprising: a dial plate; atimeindicating scale on said dial plate; a hollow stud projecting fromsaid dial plate and arranged to pass into said magazine; means forsecuring said stud to said magazine; an operating shaft extendingthroughout the length of said hollow stud; a pointer on one extremity ofsaid operating shaft and arranged to move along said timeindicatingscale; an operating arm mounted on the other extremity of said shaftwithin said magazine and positioned to contact the film roll in saidmagazine to actuate said pointer; a toothed segment gear plate movablymounted on said shaft; means for causing said gear plate to move withsaid pointer; a toothed pinion rotatably mounted on said dial plate inmesh with said segment gear plate so as to be rotated by the latter; andaudible signal means connected with and actuated by the rotation of saidtoothed pinion.

2. A film reel alarm and indicator for attachment to the film rollmagazine of a motion picture projector, comprising: a dial plate; atime-indicating scale on said dial plate; a hollow stud projecting fromsaid dial plate and arranged to pass into said magazine; means forsecuring said stud to said magazine; an operating shaft extendingthroughout the length of said hollow stud; a pointer on one extremity ofsaid operating shaft and arranged to move along said timeindicatingscale; an operating arm mounted on the other extremity of said shai'twithin said magazine and positioned to contact the film roll in saidmagazine to actuate said pointer; a toothed segment gear plate movablymounted on said shaft; means for causing said gear plate to move withsaid pointer; a toothed pinion rotatably mounted on said dial plate inmesh with said segment gear plate so as to be rotated by the latter; abell supported from said dial plate concentric with said pinion; afreely rolling ball in said bell; a ball pocket member connected withsaid toothed pinion and rotatable by the latter within said bell, saidball pocket member being positioned to receive and elevate said ball sothat the latter may drop against said bell at predetermined times.

3. A film reel alarm and indicator for attachment to the film rollmagazine of a motion picture projector, comprising: a dial plate; atimeindicating scale on said dial plate; a hollow stud projecting fromsaid dial plate and arranged to pass into said magazine; means forsecuring said stud to said magazine; an operating shaft extendingthroughout the length of said hollow stud; a pointer on one extremity ofsaid operating shaft and arranged to move along said timeindicatingscale; an operating arm mounted on the other extremity of said shaftwithin said magazine and positioned to contact the film roll in saidmagazine to actuate said pointer; a toothed segment gear plate movablymounted on said shaft; means for causing said gear plate to move withsaid pointer; a toothed pinion rotatably mounted on said dial plate inmesh with said segment gear plate so as to be rotated by the latter; abell supported from said dial plate concentric with said pinion; afreely rolling ball in said bell; a ball guide plate fixedly mountedWithin said bell; ball guide flanges projecting from said guide plate; abacking plate rotatably mounted in parallel relation to said guideplate; and a ball pocket on said backing plate; said backing plate beingmounted on said toothed pinion so that movement of said segment gearplate will rotate said backing plate to elevate the ball in said pocketto a position to allow the ball to roll on the flanges of saidstationary guide plate into contact with said bell.

4. A film reel alarm for attachment to the film roll magazine of amotion picture projector, comprising: a dome-shaped bell; a ball guideplate fixedly mounted within said bell; a backing plate rotatably andconcentrically mounted in parallel relation to said ball guide plate;means for rotating said backing plate in consequence of changes indiameter of the film roll in said magazine; a ball positioned betweensaid backing plate and said guide plate; a peripheral pocket formed onsaid backing plate adapted to receive and elevate said ball as saidbacking plate rotates; and means projecting from said fixed ball guideplate for guiding the ball during its elevation and acting to guide saidball into contact with the bell to give an audible signal.

5. A film reel alarm for attachment to the film roll magazine of amotion picture projector, comprising: a dome-shaped bell; a ball guideplate fixedly mounted within said bell; a backing plate rotatably andconcentrically mounted in parallel relation to said ball guide plate;means for rotating said backing plate in consequence of changes indiameter of the film roll in said magazine; a ball positioned betweensaid backing plate and said guide plate; a peripheral pocket formed onsaid backing plate adapted to receive and elevate said ball as saidbacking plate rotates; an arcuate guide flange projecting from saidfixed ball guide plate and adapted to guide said ball upwardly as it iselevated by said pocket; and a fixed ball chute projecting from saidball guide plate at the upper termination of said guide flange andadapted to receive and carry the ball into contact with the hell.

6. A film reel alarm for attachment to the film r011 magazine of amotion picture projector, comprising: a dome-shaped bell; a ball guideplate fixedly mounted within said bell; a backing plate rotatably andconcentrically mounted in parallel relation to said ball guide plate;means for rotating said backing plate in consequence of changes indiameter of the film roll in said magazine; a ball positioned betweensaid backing plate and said guide plate; a peripheral pocket formed onsaid backing plate adapted to receive and elevate said ball as saidbacking plate rotates; an arcuate guide flange projecting from saidfixed ball guide plate and adapted to guide said ball upwardly as it iselevated by said pocket; a fixed ball chute projecting from said ballguide plate at the upper termination of said guide flange and adapted toreceive and carry the ball into contact with the bell; and a stationaryinclined platform flange projecting from said ball plate below thetermination of said chute and arranged to receive, reverse the directionof, and guide said ball to a second contact with said bell.

7. A film reel alarm for attachment to the film roll magazine of amotion picture projector, comprising: a dome-shaped bell; a ball guideplate fixedly mounted within said bell; a backing plate rotatably andconcentrically mounted in parallel relation to said ball guide plate;means for rotating said backing plate in consequence of changes indiameter of the film roll in said magazine; a ball positioned betweensaid backing plate and said guide plate; a peripheral pocket formed onsaid backingplate adapted to receive and elevate said ball as saidbacking plate rotates; an arcuate guide flange projecting from saidfixed ball guide plate and adapted to guide said ball upwardly as it iselevated by said pocket; a fixed ball chute projecting from said ballguide plate at the upper termination of said guide flange and adapted toreceive and carry the ball into contact with the bell; a stationaryinclined platform flange projecting from said ball plate below thetermination of said chute and arranged to receive, reverse the directionof, and guide said ball to a second contact with said bell; and a bossprojecting from said backing plate and arranged to rotate into the pathof said ball at the extremity of said chute to retain the ball for atime interval.

CHARLES W. I-IATKE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name 7 Date 1,272,671 Jonson July '16, 19181,300,737 Kirk Apr. 15, 1919 2,254,326 Sontagh Sept. 2, 1941

